Background: Selectin mediated tethering represents one of the earliest steps in T cell extravasation into lymph nodes via high endothelial venules and is dependent on the biosynthesis of sialyl Lewis X (sLex) ligands by several glycosyltransferases, including two fucosyltransferases, fucosyltransferase-IV and -VII. Selectin mediated binding also plays a key role in T cell entry to inflamed organs.Methodology/Principal Findings: To understand how loss of selectin ligands (sLex) influences T cell migration to the lung, we examined fucosyltransferase-IV and -VII double knockout (FtDKO) mice. We discovered that FtDKO mice showed significant increases (,5-fold) in numbers of naïve T cells in non-inflamed lung parenchyma with no evidence of induced bronchusassociated lymphoid tissue. In contrast, activated T cells were reduced in inflamed lungs of FtDKO mice following viral infection, consistent with the established role of selectin mediated T cell extravasation into inflamed lung. Adoptive transfer of T cells into FtDKO mice revealed impaired T cell entry to lymph nodes, but selective accumulation in non-lymphoid organs. Moreover, inhibition of T cell entry to the lymph nodes by blockade of L-selectin, or treatment of T cells with pertussis toxin to inhibit chemokine dependent G-coupled receptor signaling, also resulted in increased T cells in non-lymphoid organs. Conversely, inhibition of T cell egress from lymph nodes using FTY720 agonism of S1P1 impaired T cell migration into non-lymphoid organs. Conclusions/Significance: Taken together, our results suggest that impaired T cell entry into lymph nodes via high endothelial venules due to genetic deficiency of selectin ligands results in the selective re-distribution and accumulation of T cells in non-lymphoid organs, and correlates with their increased frequency in the blood. Re-distribution of T cells into organs could potentially play a role in the initiation of T cell mediated organ diseases. © 2010 Harp, Onami.
Harp, J. R., & Onami, T. M. (2010). Naïve T cells re-distribute to the lungs of selectin ligand deficient mice. PLoS ONE, 5(6). https://doi.org/10.1371/journal.pone.0010973